I have a JLW3v3 in a Supercrew sounds single side sub box. I notice when playing music, I have a really large cabin gain hump in the sound around 60Hz. I've played with the amount of stuffing in the box, endlessly tuned the parametric EQ on my head unit, and couldn't get rid of the hump. I finally decided to take some sound deadener that I had on hand from my install, and cut up tiles to stick to the inside of the box. I covered all the areas that I could, bottom sides and front panel and rear of the box. Then I took some CCF and lined that over top of the deadener. Pulled all the stuffing out, re-installed the sub, and now I have a cleaner, better sounding sub. Is mass-loading the box the right idea though, or should I look for another solution to this problem of the 60Hz hump?

I have a JLW3v3 in a Supercrew sounds single side sub box. I notice when playing music, I have a really large cabin gain hump in the sound around 60Hz. I've played with the amount of stuffing in the box, endlessly tuned the parametric EQ on my head unit, and couldn't get rid of the hump. I finally decided to take some sound deadener that I had on hand from my install, and cut up tiles to stick to the inside of the box. I covered all the areas that I could, bottom sides and front panel and rear of the box. Then I took some CCF and lined that over top of the deadener. Pulled all the stuffing out, re-installed the sub, and now I have a cleaner, better sounding sub. Is mass-loading the box the right idea though, or should I look for another solution to this problem of the 60Hz hump?

How much air space is your box? Does it fall in the subs air space range according to JL?

Polyfill (Stuffing) is only tricking your sub to make it think there is more air space in the box that what is available.

If you put sound deadener in the box take it out. It isn't designed to go inside a box.

How much air space is your box? Does it fall in the subs air space range according to JL?

Polyfill (Stuffing) is only tricking your sub to make it think there is more air space in the box that what is available.

If you put sound deadener in the box take it out. It isn't designed to go inside a box.

Box is .65-.7 cu. ft. It does fall in the space range of the JL specs for a sealed box. You say to take it out, but after listening for a few days, it seems to have helped with the 60 Hz hump I had in the truck. I'm thinking the box itself was resonating at or near that freq., giving me that hump. I didn't put in much. Just patches on the back wall, on the front wall and on the base.

If you have limited room for a brace it doesn't have to be a full width one. You could cut strips of 3/4" strips to sort of give it ribs on the inside. I do that sometimes depending on the setup. Just wood glue them in.

If you have limited room for a brace it doesn't have to be a full width one. You could cut strips of 3/4" strips to sort of give it ribs on the inside. I do that sometimes depending on the setup. Just wood glue them in.